Display device

ABSTRACT

A novel foldable and highly portable display device is provided. Further, a novel display device capable of displaying information or the like on a seamless large screen is provided. The display device includes a flexible display panel, a first housing provided with a storage portion that includes a space in which pulled one end of the display panel is stored, a folding mechanism connected to the first housing, and a second housing connected to the folding mechanism. The other end of the display panel is connected to the second housing so that the display panel can be drawn in accordance with an opening operation of the folding mechanism and stored in accordance with a closing operation of the folding mechanism.

TECHNICAL FIELD

The present invention relates to an object, a method, or a manufacturingmethod. In addition, the present invention relates to a process, amachine, manufacture, or a composition of matter. In particular, thepresent invention relates to, for example, a semiconductor device, adisplay device, a light-emitting device, a power storage device, adriving method thereof, or a manufacturing method thereof. Inparticular, the present invention relates to a display device.

BACKGROUND ART

The social infrastructures relating to means for transmittinginformation have advanced, which allows many pieces and various kinds ofinformation to be acquired at and sent out from not only home or officebut also other visiting places.

A display device with a large screen on which much information can bedisplayed at the same time is suitable for information terminal devices.

Moreover, portable information terminal devices with which informationcan be acquired at visiting places are under active development.Portable information terminal devices are often used outdoors, and forcemight be accidentally applied to the portable information terminaldevices by dropping or the like.

As an example of a display device that can withstand external force andthus is not easily broken, a display device having high adhesivenessbetween a structure body by which a light-emitting layer is divided anda second electrode layer is known (Patent Document 1).

REFERENCE Patent Document

-   [Patent Document 1] Japanese Published Patent Application No.    2012-190794

DISCLOSURE OF INVENTION

One embodiment of the present invention is made in view of the foregoingtechnical background. One object is to provide a novel foldable andhighly portable display device. Another object is to provide a noveldisplay device capable of displaying information or the like on aseamless large screen.

Note that the descriptions of these objects do not disturb the existenceof other objects. In one embodiment of the present invention, there isno need to achieve all the objects. Other objects will be apparent fromand can be derived from the description of the specification, thedrawings, the claims, and the like.

One embodiment of the present invention includes a folding mechanism, afirst housing connected to the folding mechanism, a second housingconnected to the folding mechanism so that the second housing isconfigured to overlap with the first housing, and a flexible displaypanel configured to be stored in the first housing.

In the display device, the first housing includes a storage portion thatincludes a pulling mechanism that pulls one end of the display panel anda space in which the display panel is configured to be stored, and anopening portion connected to the storage portion. In addition, thedisplay panel is drawn from the storage portion through the openingportion. Furthermore, the other end of the display panel is connected tothe second housing so that the display panel is drawn in accordance withan opening operation of the folding mechanism and stored in accordancewith a closing operation of the folding mechanism.

One embodiment of the present invention is the above-described displaydevice in which the second housing includes a pulling mechanism thatpulls the other end of the display panel, a storage portion thatincludes a space in which the display panel is stored, and an openingportion connected to the storage portion of the second housing.

With this structure, the display device can be folded with the angle ofthe flexible display panel with respect to the housings controlled,preventing a breakage of the display panel due to application ofexcessive stress to the display panel.

Consequently, a novel foldable and highly portable display device can beprovided. Further, a novel display device capable of displayinginformation or the like on a seamless large screen can be provided.

One embodiment of the present invention is the above-described displaydevice in which at least one of the opening portions includes a guidehaving a curvature radius of more than or equal to 1 mm and less than orequal to 10 mm on the folding mechanism side.

This can prevent the curvature radius of the pulled display panel frombeing smaller than the curvature radius of the guide. As a result,application of excessive stress to the display panel can be prevented.

One embodiment of the present invention is the above-described displaydevice in which the first housing includes a window that transmitsvisible light in a position that enables the display panel stored in thestorage portion of the first housing to be observed through the window.

Thus, a display region of the display panel stored in the storageportion of the display device in the folded state can be observedthrough the window.

Note that a display device in this specification means an image displaydevice. In addition, the display device includes any of the followingmodules in its category: a module in which a connector such as aflexible printed circuit (FPC) or a tape carrier package (TCP) isattached to a display device; a module having a TCP provided with aprinted wiring board at the end thereof; and a module having anintegrated circuit (IC) directly mounted over a substrate over which alight-emitting element is formed by a chip on glass (COG) method.

With one embodiment of the present invention, a novel foldable andhighly portable display device can be provided. Further, a novel displaydevice capable of displaying information or the like on a seamless largescreen can be provided.

BRIEF DESCRIPTION OF DRAWINGS

In the accompanying drawings:

FIGS. 1A1, 1A2, 1B1, 1B2, 1C1, and 1C2 illustrate a display device of anembodiment;

FIGS. 2A and 2B illustrate structures of a storage portion in a displaydevice of an embodiment;

FIGS. 3A to 3C illustrate a structure of a display panel in a displaydevice of an embodiment;

FIGS. 4A to 4C illustrate a structure of a touch panel that can be usedin a data processing device of an embodiment;

FIGS. 5A and 5B illustrate a structure of a touch panel that can be usedin a data processing device of an embodiment;

FIGS. 6A to 6C illustrate structures of a touch panel that can be usedin a data processing device of an embodiment; and

FIGS. 7A to 7C illustrate structures of a touch panel that can be usedin a data processing device of an embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Example of Problem Solvable byOne Embodiment of the Present Invention

A flexible display panel in which a display element and the like areprovided over a flexible substrate is known.

When the flexible display panel is bent, compressive stress or tensilestress is applied to the display element and the like over the flexiblesubstrate.

When the flexible substrate is bent to such a degree as to break afunction film or a function element, a problem in which the flexiblesubstrate cannot protect the function film or the function element ofthe display panel occurs.

One Embodiment of the Present Invention

The embodiments described below include one embodiment of the presentinvention created by focusing on a structure in which bending of theflexible display panel at the time of folding housings is controlled bypulling and storing the display panel.

A display device of one embodiment of the present invention includes aflexible display panel, a first housing provided with a storage portionthat includes a space in which pulled one end of the display panel isstored, a folding mechanism connected to the first housing, and a secondhousing connected to the folding mechanism. The other end of the displaypanel is connected to the second housing so that the display panel canbe drawn in accordance with an opening operation of the foldingmechanism and stored in accordance with a closing operation of thefolding mechanism.

With this structure, the display device can be folded with the angle ofthe flexible display panel with respect to the housings controlled,preventing a breakage of the display panel due to application ofexcessive stress to the display panel.

As a result, a novel foldable and highly portable display device can beprovided. Further, a novel display device capable of displayinginformation or the like on a seamless large screen can be provided.

Embodiments will be described in detail with reference to drawings. Notethat the present invention is not limited to the description below, andit is easily understood by those skilled in the art that various changesand modifications can be made without departing from the spirit andscope of the present invention. Therefore, the present invention shouldnot be construed as being limited to the description in the followingembodiments. Note that in the structures of the present inventiondescribed below, the same portions or portions having similar functionsare denoted by the same reference numerals throughout differentdrawings, and description of such portions will not be repeated.

Embodiment 1

In this embodiment, a structure of a display device of one embodiment ofthe present invention will be described with reference to FIGS. 1A1,1A2, 1B1, 1B2, 1C1, and 1C2 and FIGS. 2A and 2B.

FIGS. 1A1, 1B1, and 1C1 are plan views of the display device of oneembodiment of the present invention. FIGS. 1A2, 1B2, and 1C2 are sideviews corresponding to FIGS. 1A1, 1B1, and 1C1, respectively.

FIGS. 1A1 and 1A2 illustrate a state in which the display device of oneembodiment of the present invention is developed.

FIGS. 1B1 and 1B2 illustrate a state in which the display device of oneembodiment of the present invention is folded halfway.

FIGS. 1C1 and 1C2 illustrate a state in which the display device of oneembodiment of the present invention is folded up.

FIGS. 2A and 2B schematically illustrate structures of a storage portionthat can be employed in the display device of one embodiment of thepresent invention.

A display device 500 described in this embodiment includes a foldingmechanism 550, a first housing 510L connected to the folding mechanism550, a second housing 510R connected to the folding mechanism 550 so asto overlap with the first housing 510L when the display device 500 isfolded, and a flexible display panel 200 that is stored in the firsthousing 510L (see FIGS. 1A1, 1A2, 1B1, 1B2, 1C1, and 1C2). Note that thedisplay panel 200 includes a display region 201 that can displayinformation or the like.

The first housing 510L includes a pulling mechanism 521L that pulls oneend 200L of the display panel 200, a storage portion 520L that includesa space in which the display panel 200 is stored, and an opening portion515L connected to the storage portion 520L (see FIG. 2A).

The display panel 200 is drawn from the storage portion 520L through theopening portion 515L. The other end 200R is connected to the secondhousing 510R so that the display panel 200 is drawn in accordance withan opening operation of the folding mechanism 550 and stored inaccordance with a closing operation of the folding mechanism 550 (seeFIGS. 1A1, 1A2, 1B1, 1B2, 1C1, and 1C2).

With this structure, the flexible display panel 200 can be stored in thestorage portion 520L from the end 200L side. In addition, the displaydevice can be folded with the angle of the flexible display panel 200with respect to the housings controlled. In addition, a breakage of thedisplay panel 200 due to application of excessive stress can beprevented.

In the display device 500 described as an example in this embodiment,the second housing 510R is provided with a pulling mechanism that pullsthe other end 200R of the display panel 200, a storage portion 520Rincluding a space in which the display panel 200 is stored, and anopening portion 515R connected to the storage portion 520R (see FIGS.1A1, 1A2, 1B1, 1B2, 1C1, and 1C2 and FIG. 3A).

With this structure, the flexible display panel 200 can be stored in thestorage portion 520L and the storage portion 520R from the end 200L sideand the end 200R side, respectively. In addition, the display device canbe folded with the angle of the flexible display panel 200 with respectto the housings controlled. In addition, a breakage of the display panel200 due to application of excessive stress can be prevented.

Consequently, the novel foldable and highly portable display device 500can be provided. Furthermore, the novel display device 500 capable ofdisplaying information or the like on a seamless large screen can beprovided.

In the display device 500 described as an example in this embodiment, awindow 518L that transmits visible light is provided in the firsthousing 510L in a position that enables the display panel 200 stored inthe storage portion 520L to be observed through the window 518L (seeFIGS. 1C1 and 1C2).

Thus, the display region 201 of the display panel 200 stored in thestorage portion 520L of the display device 500 in the folded state canbe observed through the window 518L.

Consequently, the novel foldable and highly portable display device 500can be provided. Furthermore, the novel display device 500 capable ofdisplaying information or the like on a seamless large screen can beprovided. Moreover, the novel display device 500 whose displayedinformation is visible in the folded state can be provided.

Individual components of the display device of one embodiment of thepresent invention will be described below.

<<Storage Portion>>

The storage portion 520L includes a space in which the pulling mechanism521L and the display panel 200 are stored (see FIG. 2A). The space has asize that allows the display panel 200 to be stored therein; a size thatallows storage of the display panel 200 in a bent state or in a rolledstate may be employed.

<<Pulling Mechanism>>

The pulling mechanism 521L pulls the end 200L of the display panel 200.As the pulling mechanism 521L, a tension spring, a spool, or the likecan be used, for example.

For example, a tension spring whose one end is fixed to the firsthousing 510L can be used as the pulling mechanism 521L. The other end ofthe tension spring is connected to the end 200L of the display panel200. With this structure, the tension spring is extended more as thedisplay panel 200 is drawn more from the opening portion 515L. Inaddition, the tension spring pulls the drawn display panel 200 back tothe space of the storage portion 520L.

Furthermore, the first housing 510L may be provided with a slider 523Lthat slides in a direction in which the pulling mechanism 521L pulls anda rail 525L that guides the slider 523L. In this case, an operation ofdrawing the display panel 200 and an operation of pulling back thedisplay panel 200 by the pulling mechanism 521L can be performed stably.

This can prevent a problem such as unintentional bending of the displaypanel 200 in the storage portion 520L or the like in the foldingoperation of the display panel 200.

<<Opening Portion>>

The opening portion 515L is provided on one surface of the first housing510L and connects the space of the storage portion 520L to the outsideof the first housing 510L. In addition, the opening portion 515L has asize that allows the display panel 200 to be drawn from the storageportion 520L.

The opening portion 515L is provided with a guide 516L having acurvature radius of more than or equal to 1 mm and less than or equal to10 mm on the folding mechanism 550 side, i.e., on the side in contactwith the display panel 200 (see FIG. 2A).

This can prevent the curvature radius of the pulled display panel 200from being smaller than the curvature radius of the guide 516L.Consequently, unintentional bending or application of excessive stressto the display panel 200 can be prevented.

Note that instead of the guide 516L, a cylindrical guide 516L(2) that isrotatably supported can be used (see FIG. 2B). When the guide 516L(2) isrotatably supported, a friction between the guide 516L(2) and a rearsurface of the display panel 200 can be reduced.

Note that the radius of the cylindrical guide 516L(2) is preferably morethan or equal to 1 mm and less than or equal to 10 mm.

<<Window>>

The window 518L transmits visible light.

The window 518L is provided on a surface of the first housing 510L thatis opposite to the surface that faces the second housing 510R in thefolded state so that the display region 201 of the stored display panel200 can be observed through the window 518L (see FIGS. 1C1 and 1C2).Note that the first housing 510L is provided with the window 518Lthrough which the display panel 200 can be observed from the sidesurface 510L(a) side and the side surface 510L(b) side.

Thus, a user can view and use information displayed on the displaydevice 500 in the folded state.

<<Folding Mechanism>>

With the folding mechanism 550, the second housing 510R can be folded soas to overlap with the first housing 510L. For example, a hinge, aflexible member, or the like can be used as the folding mechanism 550.

Note that the folding mechanism 550 may be provided with a ratchetmechanism, a unit to prevent slipping, or the like in order toappropriately adjust the angle of the second housing 510R with respectto the first housing 510L.

<<Display Panel>>

The display panel 200 is flexible. One end 200L of the display panel 200is connected to the pulling mechanism 521L, and the other end 200Rthereof is connected to the second housing 510R.

The display panel 200 that can be used in the display device 500includes a display element that can display information contained in asupplied signal. As the display element, a light-emitting element,electronic ink, a liquid crystal element, or the like is used, forexample. Note that an example of the display panel 200 includinglight-emitting elements as display elements will be described in detailin Embodiment 2.

Usage modes of the display device 500 of one embodiment of the presentinvention will be described below.

<<Usage Mode 1>>

The first housing 510L and the second housing 510R are developed usingthe folding mechanism 550 as an axis (see FIGS. 1A1 and 1A2).

The display region 201 of the display panel 200 extends over the firsthousing 510L and the second housing 510R and displays images or the likein a direction indicated by arrows in FIG. 1A2. Note that since thedisplay region 201 is seamless, favorable display with less visualdiscomfort due to gaps or joints can be performed. Furthermore, sincethe flexible display panel 200 is kept tightened by the tension appliedby the pulling mechanism 521L, favorable display with less visualdiscomfort due to panel distortion can be performed. Moreover, since oneend of the display region 201 reaches the opening portion 515L and theother end of the display region 201 reaches the opening portion 515R, anarrow bezel of the display region 201 can be achieved.

<<Usage Mode 2>>

The first housing 510L and the second housing 510R are folded in adirection indicated by an arc-shaped dashed arrow in FIG. 1B2, using thefolding mechanism 550 as an axis (also see FIG. 1B1).

The display panel 200 is stored in the storage portion 520L and thestorage portion 520R in accordance with the reduced length between theopening portion 515L of the first housing 510L and the opening portion515R of the second housing 510R. The flexible display panel 200 isstretched tight and extends between the opening portion 515L and theopening portion 515R by the tension applied by the pulling mechanism521L in a direction indicated by a linear dashed arrow. Note that thedisplay panel 200 displays images or the like in a direction indicatedby an open arrow in FIG. 1B2.

When the display device 500 is placed on a desk for example, this usagemode allows the angle of the display panel to be adjusted so that a usercan view the display panel in a comfortable position. In addition, auser can appropriately adjust the size of a screen on which informationor the like is displayed in accordance with the displayed information.Specifically, the aspect ratio can be adjusted to 4:3, 16:9, or 16:10,for example.

<<Usage Mode 3>>

The first housing 510L and the second housing 510R are folded using thefolding mechanism 550 as an axis (see FIGS. 1C1 and 1C2).

The display region 201 of the display panel 200 stored in the firsthousing 510L can be observed through the window 518L. Note that thedisplay region 201 of the display panel 200 is driven so as to displayinformation in a region that is observed from the window 518L and so asnot to display information in the other region. In this manner, powerconsumption can be reduced.

Thus, the display region 201 of the display panel 200 stored in thestorage portion 520L of the display device 500 in the folded state canbe used by being viewed through the window 518L.

This embodiment can be implemented in appropriate combination with anyof the other embodiments in this specification.

Embodiment 2

In this embodiment, a structure of a display panel that can be used inthe display device of one embodiment of the present invention will bedescribed with reference to FIGS. 3A to 3C.

FIG. 3A is a plan view illustrating the structure of a display panelthat can be used in the display device of one embodiment of the presentinvention.

FIG. 3B is a cross-sectional view taken along line A-B and line C-D inFIG. 3A.

FIG. 3C is a cross-sectional view taken along line E-F in FIG. 3A.

<Plan View>

The display panel 200 described as an example in this embodimentincludes one end 200L and the other end 200R (see FIG. 3A).

Furthermore, the display panel 200 described as an example in thisembodiment includes the display region 201.

In the display region 201, a plurality of pixels 202 is provided, and aplurality of sub-pixels (e.g., a sub-pixel 202R) is provided in each ofthe pixels 202. In addition, in the sub-pixels, light-emitting elementsand pixel circuits that can supply electric power for driving thelight-emitting elements are provided.

The pixel circuits are electrically connected to wirings through whichselection signals are supplied and wirings through which data signalsare supplied.

Furthermore, the display panel 200 is provided with a scan line drivercircuit 203 g that can supply selection signals and a data line drivercircuit 203 s that can supply data signals.

<Cross-Sectional View>

The display panel 200 includes a substrate 210 and a counter substrate270 that faces the substrate 210 (see FIG. 3B).

The substrate 210 is a stacked body including a flexible substrate 210b, a barrier film 210 a that prevents diffusion of unintentionalimpurities to the light-emitting elements, and an adhesive layer 210 cthat attaches the barrier film 210 a to the substrate 210 b.

The counter substrate 270 is a stacked body including a flexiblesubstrate 270 b, a barrier film 270 a that prevents diffusion ofunintentional impurities to the light-emitting elements, and an adhesivelayer 270 c that attaches the barrier film 270 a to the substrate 270 b.

A sealant 260 that also serves as an optical adhesive layer attaches thecounter substrate 270 to the substrate 210. The pixel circuits and thelight-emitting elements (e.g., a first light-emitting element 250R) areprovided between the substrate 210 and the counter substrate 270.

<<Structure of Pixel>>

Each of the pixels 202 includes a sub-pixel 202R, a sub-pixel 202G, anda sub-pixel 202B (see FIG. 3C). The sub-pixel 202R includes alight-emitting module 280R, the sub-pixel 202G includes a light-emittingmodule 280G, and the sub-pixel 202B includes a light-emitting module280B.

For example, the sub-pixel 202R includes the first light-emittingelement 250R and the pixel circuit that can supply electric power to thefirst light-emitting element 250R and includes a transistor 202 t (seeFIG. 3B). Furthermore, the sub-pixel 202R includes the light-emittingmodule 280R, and the light-emitting module 280R includes the firstlight-emitting element 250R and an optical element (e.g., a firstcoloring layer 267R).

The first light-emitting element 250R includes a first lower electrode251R, an upper electrode 252, and a layer 253 containing alight-emitting organic compound between the first lower electrode 251Rand the upper electrode 252.

The layer 253 containing a light-emitting organic compound includes alight-emitting unit 253 a, a light-emitting unit 253 b, and anintermediate layer 254 between the light-emitting units 253 a and 253 b.

The light-emitting module 280R includes the first coloring layer 267R onthe counter substrate 270. The coloring layer transmits light of aparticular wavelength and is, for example, a layer that selectivelytransmits light of red, green, or blue color. Note that a region thattransmits light emitted from the light-emitting element as it is may beprovided as well.

The light-emitting module 280R, for example, includes the sealant 260that also serves as an optical adhesive layer and is in contact with thefirst light-emitting element 250R and the first coloring layer 267R.

The first coloring layer 267R is positioned in a region overlapping withthe first light-emitting element 250R. Accordingly, part of lightemitted from the first light-emitting element 250R passes through thesealant 260 that also serves as an optical adhesive layer and throughthe first coloring layer 267R and is emitted to the outside of thelight-emitting module 280R as indicated by arrows in FIGS. 3B and 3C.

<<Structure of Display Panel>>

The display panel 200 includes a light-blocking layer 267BM on thecounter substrate 270. The light-blocking layer 267BM is provided so asto surround the coloring layer (e.g., the first coloring layer 267R).

The display panel 200 includes an anti-reflective layer 267 p positionedin a region overlapping with the display region 201.

The display panel 200 includes an insulating film 221. The insulatingfilm 221 covers the transistor 202 t. Note that the insulating film 221can be used as a layer for planarizing unevenness caused by the pixelcircuits. An insulating film on which a layer that can prevent diffusionof impurities to the transistor 202 t and the like is stacked can beused as the insulating film 221.

The display panel 200 includes the light-emitting elements (e.g., thefirst light-emitting element 250R) over the insulating film 221.

The display panel 200 includes, over the insulating film 221, apartition wall 228 that overlaps with an end portion of the first lowerelectrode 251R (see FIG. 3C). In addition, a spacer 229 that controlsthe distance between the substrate 210 and the counter substrate 270 isprovided on the partition wall 228.

<<Structure of Data Line Driver Circuit>>

The data line driver circuit 203 s includes a transistor 203 t and acapacitor 203 c. Note that the driver circuit can be formed in the sameprocess and over the same substrate as those of the pixel circuits.

<<Other Structures>>

The display panel 200 includes a wiring 211 through which a signal canbe supplied. The wiring 211 is provided with a terminal 219. Note that aflexible printed circuit (FPC) 209 through which a signal such as a datasignal or a synchronization signal can be supplied is electricallyconnected to the terminal 219.

Note that a printed wiring board (PWB) may be attached to the FPC. Thelight-emitting device in this specification includes, in its category,not only a light-emitting device itself but also a light-emitting deviceprovided with an FPC or a PWB.

This embodiment can be implemented in appropriate combination with anyof the other embodiments in this specification.

Embodiment 3

In this embodiment, a structure of a display portion that can be used inthe display device of one embodiment of the present invention and astructure of a foldable touch panel that can be used in a positionalinformation input portion will be described with reference to FIGS. 4Ato 4C.

FIGS. 4A to 4C illustrate the structure of a touch panel that can beused in a data processing device in one embodiment of the presentinvention.

FIG. 4A is a plan view and FIG. 4B is a cross-sectional view taken alongline A-B and line C-D in FIG. 4A.

FIG. 4C is a cross-sectional view taken along line E-F in FIG. 4A.

<Plan View>

A touch panel 300 described as an example in this embodiment includes adisplay portion 301 (see FIG. 4A).

The display portion 301 includes a plurality of pixels 302 and aplurality of imaging pixels 308. The imaging pixels 308 can sense atouch of a finger or the like on the display portion 301. Thus, a touchsensor can be formed using the imaging pixels 308.

Each of the pixels 302 includes a plurality of sub-pixels (e.g., asub-pixel 302R). In addition, in the sub-pixels, light-emitting elementsand pixel circuits that can supply electric power for driving thelight-emitting elements are provided.

The pixel circuits are electrically connected to wirings through whichselection signals are supplied and wirings through which image signalsare supplied.

Furthermore, the touch panel 300 is provided with a scan line drivercircuit 303 g(1) that can supply selection signals to the pixels 302 andan image signal line driver circuit 303 s(1) that can supply imagesignals to the pixels 302.

The imaging pixels 308 include photoelectric conversion elements andimaging pixel circuits that drive the photoelectric conversion elements.

The imaging pixel circuits are electrically connected to wirings throughwhich control signals are supplied and wirings through which powersupply potentials are supplied.

Examples of the control signals include a signal for selecting animaging pixel circuit from which a recorded imaging signal is read, asignal for initializing an imaging pixel circuit, and a signal fordetermining the time it takes for an imaging pixel circuit to detectlight.

The touch panel 300 is provided with an imaging pixel driver circuit 303g(2) that can supply control signals to the imaging pixels 308 and animaging signal line driver circuit 303 s(2) that reads out imagingsignals.

<Cross-Sectional View>

The touch panel 300 includes a substrate 310 and a counter substrate 370that faces the substrate 310 (see FIG. 4B).

By using a flexible material as the substrate 310 and the countersubstrate 370, the touch panel 300 can have flexibility.

Note that when the flexible touch panel 300 is bent, stress is appliedto a function element provided in the touch panel 300. A functionelement is preferably positioned in the center between the substrate 310and the counter substrate 370 because a change in shape of the functionelement can be prevented.

Furthermore, the substrate 310 is preferably formed using a materialwhose coefficient of linear expansion is substantially equal to that ofthe counter substrate 370. For example, the coefficient of linearexpansion of the materials are preferably lower than or equal to1×10⁻³/K, further preferably lower than or equal to 5×10⁻⁵/K, and stillfurther preferably lower than or equal to 1×10⁻⁵/K.

For example, materials that include polyester, polyolefin, polyamide(e.g., nylon, aramid), polyimide, polycarbonate, or a resin having anacrylic bond, an urethane bond, an epoxy bond, or a siloxane bond can beused for the substrate 310 and the counter substrate 370.

The substrate 310 is a stacked body in which a flexible substrate 310 b,a barrier film 310 a that prevents diffusion of unintentional impuritiesto the light-emitting elements, and a resin layer 310 c that attachesthe barrier film 310 a to the substrate 310 b are stacked.

The counter substrate 370 is a stacked body including a flexiblesubstrate 370 b, a barrier film 370 a that prevents diffusion ofunintentional impurities to the light-emitting elements, and a resinlayer 370 c that attaches the barrier film 370 a to the substrate 370 b(see FIG. 4B).

A sealant 360 attaches the counter substrate 370 to the substrate 310.The sealant 360 also serving as an optical adhesive layer has arefractive index higher than that of air. The pixel circuits and thelight-emitting elements (e.g., a first light-emitting element 350R) areprovided between the substrate 310 and the counter substrate 370.

<<Structure of Pixel>>

Each of the pixels 302 includes a sub-pixel 302R, a sub-pixel 302G, anda sub-pixel 302B (see FIG. 4C). The sub-pixel 302R includes alight-emitting module 380R, the sub-pixel 302G includes a light-emittingmodule 380G, and the sub-pixel 302B includes a light-emitting module380B.

For example, the sub-pixel 302R includes the first light-emittingelement 350R and the pixel circuit that can supply electric power to thefirst light-emitting element 350R and includes a transistor 302 t (seeFIG. 4B). Furthermore, the light-emitting module 380R includes the firstlight-emitting element 350R and an optical element (e.g., a firstcoloring layer 367R).

The first light-emitting element 350R includes a first lower electrode351R, an upper electrode 352, and a layer 353 containing alight-emitting organic compound between the first lower electrode 351Rand the upper electrode 352 (see FIG. 4C).

The layer 353 containing a light-emitting organic compound includes alight-emitting unit 353 a, a light-emitting unit 353 b, and anintermediate layer 354 between the light-emitting units 353 a and 353 b.

The light-emitting module 380R includes the first coloring layer 367R onthe counter substrate 370. The coloring layer transmits light of aparticular wavelength and is, for example, a layer that selectivelytransmits light of red, green, or blue color. Note that a region thattransmits light emitted from the light-emitting element as it is may beprovided as well.

The light-emitting module 380R, for example, includes the sealant 360that is in contact with the first light-emitting element 350R and thefirst coloring layer 367R.

The first coloring layer 367R is positioned in a region overlapping withthe first light-emitting element 350R. Accordingly, part of lightemitted from the first light-emitting element 350R passes through thesealant 360 that also serves as an optical adhesive layer and throughthe first coloring layer 367R and is emitted to the outside of thelight-emitting module 380R as indicated by arrows in FIGS. 4B and 4C.

<<Structure of Touch Panel>>

The touch panel 300 includes a light-blocking layer 367BM on the countersubstrate 370. The light-blocking layer 367BM is provided so as tosurround the coloring layer (e.g., the first coloring layer 367R).

The touch panel 300 includes an anti-reflective layer 367 p positionedin a region overlapping with the display portion 301. As theanti-reflective layer 367 p, a circular polarizing plate can be used,for example.

The touch panel 300 includes an insulating film 321. The insulating film321 covers the transistor 302 t. Note that the insulating film 321 canbe used as a layer for planarizing unevenness caused by the pixelcircuits. An insulating film on which a layer that can prevent diffusionof impurities to the transistor 302 t and the like is stacked can beused as the insulating film 321.

The touch panel 300 includes the light-emitting elements (e.g., thefirst light-emitting element 350R) over the insulating film 321.

The touch panel 300 includes, over the insulating film 321, a partitionwall 328 that overlaps with an end portion of the first lower electrode351R (see FIG. 4C). In addition, a spacer 329 that controls the distancebetween the substrate 310 and the counter substrate 370 is provided onthe partition wall 328.

<<Structure of Image Signal Line Driver Circuit>>

The image signal line driver circuit 303 s(1) includes a transistor 303t and a capacitor 303 c. Note that the driver circuit can be formed inthe same process and over the same substrate as those of the pixelcircuits.

<<Structure of Imaging Pixel>>

The imaging pixels 308 each include a photoelectric conversion element308 p and an imaging pixel circuit for sensing light received by thephotoelectric conversion element 308 p. The imaging pixel circuitincludes a transistor 308 t.

For example, a PIN photodiode can be used as the photoelectricconversion element 308 p.

<<Other Structures>>

The touch panel 300 includes a wiring 311 through which a signal can besupplied. The wiring 311 is provided with a terminal 319. Note that anFPC 309(1) through which a signal such as an image signal or asynchronization signal can be supplied is electrically connected to theterminal 319.

Note that a printed wiring board (PWB) may be attached to the FPC309(1).

Transistors formed in the same process can be used as the transistor 302t, the transistor 303 t, the transistor 308 t, and the like.

Transistors of a bottom-gate type, a top-gate type, or the like can beused.

Any of various kinds of semiconductors can be used in the transistors.For example, an oxide semiconductor, single crystal silicon,polysilicon, amorphous silicon, or the like can be used.

This embodiment can be implemented in appropriate combination with anyof the other embodiments in this specification.

Embodiment 4

In this embodiment, a structure of a foldable touch panel that can beused in the display device of one embodiment of the present inventionwill be described with reference to FIGS. 5A and 5B and FIGS. 6A to 6C.

FIGS. 5A and 5B are perspective views illustrating typical components ofa touch panel in one embodiment of the present invention. FIG. 5A is aperspective view of a touch panel 400, and FIG. 5B is a perspective viewillustrating the components of the touch panel 400 in a separated state.

FIGS. 6A to 6C are cross-sectional views of the touch panel 400 takenalong line X1-X2 in FIG. 5A.

The touch panel 400 includes a display portion 401 and a touch sensor495 (see FIG. 5B). Furthermore, the touch panel 400 includes a substrate410, a substrate 470, and a substrate 490. Note that the substrate 410,the substrate 470, and the substrate 490 each have flexibility.

The display portion 401 includes the substrate 410, a plurality ofpixels over the substrate 410, and a plurality of wirings 411 throughwhich signals are supplied to the pixels. The plurality of wirings 411is led to a peripheral portion of the substrate 410, and part of theplurality of wirings 411 forms a terminal 419. The terminal 419 iselectrically connected to an FPC 409(1).

<Touch Sensor>

The substrate 490 includes the touch sensor 495 and a plurality ofwirings 498 electrically connected to the touch sensor 495. Theplurality of wirings 498 is led to a peripheral portion of the substrate490, and part of the plurality of wirings 498 forms a terminal. Theterminal is electrically connected to an FPC 409(2). Note that in FIG.5B, electrodes, wirings, and the like of the touch sensor 495 providedon the back side of the substrate 490 (the side opposite to the viewerside) are indicated by solid lines for clarity.

As the touch sensor 495, a capacitive touch sensor can be used. Examplesof the capacitive touch sensor are a surface capacitive touch sensor anda projected capacitive touch sensor.

Examples of the projected capacitive touch sensor are a self capacitivetouch sensor and a mutual capacitive touch sensor, which differ mainlyin the driving method. The use of a mutual capacitive touch sensor ispreferable because multiple points can be sensed simultaneously.

An example of using a projected capacitive touch sensor will bedescribed below with reference to FIG. 5B.

Note that a variety of sensors that can sense the closeness or thecontact of a sensing target such as a finger, can be used.

The projected capacitive touch sensor 495 includes electrodes 491 andelectrodes 492. The electrodes 491 are electrically connected to any ofthe plurality of wirings 498, and the electrodes 492 are electricallyconnected to any of the other wirings 498.

The electrodes 492 each have a shape of a plurality of quadranglesarranged in one direction with one corner of a quadrangle connected toone corner of another quadrangle as illustrated in FIGS. 5A and 5B.

A plurality of electrodes 491 each have a quadrangular shape and arearranged in a direction intersecting with the direction in which theelectrodes 492 extend.

A wiring 494 electrically connects two electrodes 491 between which theelectrode 492 is positioned. The intersecting area of the electrode 492and the wiring 494 is preferably as small as possible. Such a structureallows a reduction in the area of a region where the electrodes are notprovided, reducing unevenness in transmittance. As a result, unevennessin luminance of light from the touch sensor 495 can be reduced.

Note that the shapes of the electrodes 491 and the electrodes 492 arenot limited to the above-mentioned shapes and can be any of a variety ofshapes. For example, the plurality of electrodes 491 may be provided sothat space between the electrodes 491 are reduced as much as possible,and a plurality of electrodes 492 may be provided with an insulatinglayer sandwiched between the electrodes 491 and the electrodes 492 andmay be spaced apart from each other to form a region not overlappingwith the electrodes 491. In that case, between two adjacent electrodes492, it is preferable to provide a dummy electrode which is electricallyinsulated from these electrodes, whereby the area of a region having adifferent transmittance can be reduced.

A structure of the touch sensor 495 will be described with reference toFIGS. 6A to 6C.

The touch sensor 495 includes the substrate 490, the electrodes 491 andthe electrodes 492 provided in a staggered arrangement on the substrate490, an insulating layer 493 covering the electrodes 491 and theelectrodes 492, and the wiring 494 that electrically connects theadjacent electrodes 491 to each other.

A resin layer 497 attaches the substrate 490 to the substrate 470 sothat the touch sensor 495 overlaps with the display portion 401.

The electrodes 491 and the electrodes 492 are formed using alight-transmitting conductive material. As the light-transmittingconductive material, a conductive oxide such as indium oxide, indium tinoxide, indium zinc oxide, zinc oxide, or zinc oxide to which gallium isadded can be used. Note that a film including graphene may be used aswell. The film including graphene can be formed, for example, byreducing a film containing graphene oxide. As a reducing method, amethod with application of heat or the like can be employed.

The electrodes 491 and the electrodes 492 may be formed by depositing alight-transmitting conductive material on the substrate 490 by asputtering method and then removing an unnecessary portion by any ofvarious patterning techniques such as photolithography.

Examples of a material for the insulating layer 493 are a resin such asacrylic or epoxy resin, a resin having a siloxane bond, and an inorganicinsulating material such as silicon oxide, silicon oxynitride, oraluminum oxide.

Furthermore, openings reaching the electrodes 491 are formed in theinsulating layer 493, and the wiring 494 electrically connects theadjacent electrodes 491. A light-transmitting conductive material can befavorably used as the wiring 494 because the aperture ratio of the touchpanel can be increased. Moreover, a material with higher conductivitythan the conductivities of the electrodes 491 and 492 can be favorablyused because electric resistance can be reduced.

One electrode 492 extends in one direction, and a plurality ofelectrodes 492 is provided in the form of stripes.

The wiring 494 intersects with the electrode 492.

Adjacent electrodes 491 are provided with one electrode 492 providedtherebetween. The wiring 494 electrically connects the adjacentelectrodes 491.

Note that the plurality of electrodes 491 is not necessarily arranged inthe direction orthogonal to one electrode 492 and may be arranged tointersect with one electrode 492 at an angle of less than 90 degrees.

One wiring 498 is electrically connected to any of the electrodes 491and 492. Part of the wiring 498 serves as a terminal. For the wiring498, a metal material such as aluminum, gold, platinum, silver, nickel,titanium, tungsten, chromium, molybdenum, iron, cobalt, copper, orpalladium or an alloy material containing any of these metal materialscan be used.

Note that an insulating layer that covers the insulating layer 493 andthe wiring 494 may be provided to protect the touch sensor 495.

Furthermore, a connection layer 499 electrically connects the wiring 498to the FPC 409(2).

As the connection layer 499, any of various anisotropic conductive films(ACF), anisotropic conductive pastes (ACP), or the like can be used.

The resin layer 497 has a light-transmitting property. For example, athermosetting resin or an ultraviolet curable resin can be used;specifically, a resin such as acrylic, urethane, epoxy resin, or a resinhaving a siloxane bond can be used.

Display Portion

The display portion 401 includes a plurality of pixels arranged in amatrix. Each of the pixels includes a display element and a pixelcircuit for driving the display element.

In this embodiment, an example of using an organic electroluminescentelement that emits white light as a display element will be described;however, the display element is not limited to such element.

For example, organic electroluminescent elements that emit light ofdifferent colors may be included in sub-pixels so that the light ofdifferent colors can be emitted from the respective sub-pixels.

Other than organic electroluminescent elements, any of various displayelements such as display elements (electronic ink) that perform displayby an electrophoretic method, an electronic liquid powder method, anelectrowetting method, or the like; MEMS shutter display elements;optical interference type MEMS display elements; and liquid crystalelements can be used. Furthermore, this embodiment can be used in atransmissive liquid crystal display, a transflective liquid crystaldisplay, a reflective liquid crystal display, a direct-view liquidcrystal display, or the like. In the case of a transflective liquidcrystal display or a reflective liquid crystal display, some of or allof pixel electrodes function as reflective electrodes. For example, someor all of pixel electrodes are formed to contain aluminum, silver, orthe like. In such a case, a memory circuit such as an SRAM can beprovided under the reflective electrodes, leading to lower powerconsumption. A structure suitable for employed display elements can beselected from among a variety of structures of pixel circuits.

In the display portion, an active matrix method in which an activeelement is included in a pixel or a passive matrix method in which anactive element is not included in a pixel can be used.

In an active matrix method, as an active element (a non-linear element),not only a transistor but also various active elements (non-linearelements) can be used. For example, an MIM (metal insulator metal), aTFD (thin film diode), or the like can also be used. Since theseelements can be formed with a smaller number of manufacturing steps,manufacturing cost can be reduced or yield can be improved. Furthermore,since the size of these elements is small, the aperture ratio can beimproved, so that power consumption can be reduced or higher luminancecan be achieved.

As a method other than an active matrix method, a passive matrix methodin which an active element (a non-linear element) is not used can alsobe used. Since an active element (a non-linear element) is not used, thenumber of manufacturing steps is small, so that manufacturing cost canbe reduced or yield can be improved. Furthermore, since an activeelement (a non-linear element) is not used, the aperture ratio can beimproved, so that power consumption can be reduced or higher luminancecan be achieved, for example.

Flexible materials can be favorably used in the substrate 410 and thesubstrate 470.

Materials with which unintended passage of impurities is inhibited canbe favorably used in the substrate 410 and the substrate 470. Forexample, materials with a vapor permeability of lower than or equal to10⁻⁵ g/m² day, preferably lower than or equal to 10⁻⁶ g/m² day can befavorably used.

The substrate 410 can be favorably formed using a material whosecoefficient of linear expansion is substantially equal to that of thesubstrate 470. For example, the coefficient of linear expansion of thematerials are preferably lower than or equal to 1×10⁻³/K, furtherpreferably lower than or equal to 5×10⁻⁵/K, and still further preferablylower than or equal to 1×10⁻⁵/K.

The substrate 410 is a stacked body in which a flexible substrate 410 b,a barrier film 410 a that prevents diffusion of unintentional impuritiesto light-emitting elements, and a resin layer 410 c that attaches thebarrier film 410 a to the substrate 410 b are stacked.

For example, materials that include polyester, polyolefin, polyamide(e.g., nylon, aramid), polyimide, polycarbonate, or a resin having anacrylic bond, an urethane bond, an epoxy bond, or a siloxane bond can beused for the resin layer 410 c.

The substrate 470 is a stacked body in which a flexible substrate 470 b,a barrier film 470 a that prevents diffusion of unintentional impuritiesto the light-emitting elements, and a resin layer 470 c that attachesthe barrier film 470 a to the substrate 470 b are stacked.

A sealant 460 attaches the substrate 470 to the substrate 410. Thesealant 460 has a refractive index higher than that of air. In the caseof extracting light to the sealant 460 side, the sealant 460 serves asan optical adhesive layer. The pixel circuits and the light-emittingelements (e.g., a first light-emitting element 450R) are providedbetween the substrate 410 and the substrate 470.

<<Structure of Pixel>>

A pixel includes a sub-pixel 402R, and the sub-pixel 402R includes alight-emitting module 480R.

The sub-pixel 402R includes the first light-emitting element 450R andthe pixel circuit that can supply electric power to the firstlight-emitting element 450R and includes a transistor 402 t.Furthermore, the light-emitting module 480R includes the firstlight-emitting element 450R and an optical element (e.g., a firstcoloring layer 467R).

The first light-emitting element 450R includes a lower electrode, anupper electrode, and a layer containing a light-emitting organiccompound between the lower electrode and the upper electrode.

The light-emitting module 480R includes the first coloring layer 467R onthe light extraction side. The coloring layer transmits light of aparticular wavelength and is, for example, a layer that selectivelytransmits light of red, green, or blue color. Note that in anothersub-pixel, a region that transmits light emitted from the light-emittingelement as it is may be provided as well.

In the case where the sealant 460 is provided on the light extractionside, the sealant 460 is in contact with the first light-emittingelement 450R and the first coloring layer 467R.

The first coloring layer 467R is positioned in a region overlapping withthe first light-emitting element 450R. Accordingly, part of lightemitted from the first light-emitting element 450R passes through thefirst coloring layer 467R and is emitted to the outside of thelight-emitting module 480R as indicated by an arrow in FIG. 6A.

<<Structure of Display Portion>>

The display portion 401 includes a light-blocking layer 467BM on thelight extraction side. The light-blocking layer 467BM is provided so asto surround the coloring layer (e.g., the first coloring layer 467R).

The display portion 401 includes an anti-reflective layer 467 ppositioned in a region overlapping with pixels. As the anti-reflectivelayer 467 p, a circular polarizing plate can be used, for example.

The display portion 401 includes an insulating film 421. The insulatingfilm 421 covers the transistor 402 t. Note that the insulating film 421can be used as a layer for planarizing unevenness caused by the pixelcircuits. A stacked film including a layer that can prevent diffusion ofimpurities can be used as the insulating film 421. This can prevent thereliability of the transistor 402 t or the like from being lowered bydiffusion of unintentional impurities.

The display portion 401 includes the light-emitting elements (e.g., thefirst light-emitting element 450R) over the insulating film 421.

The display portion 401 includes, over the insulating film 421, apartition wall 428 that overlaps with an end portion of the lowerelectrode. In addition, a spacer that controls the distance between thesubstrate 410 and the substrate 470 is provided on the partition wall428.

<<Structure of Scan Line Driver Circuit>>

A scan line driver circuit 403 g(1) includes a transistor 403 t and acapacitor 403 c. Note that the driver circuit can be formed in the sameprocess and over the same substrate as those of the pixel circuits.

<<Other Structures>>

The display portion 401 includes the wirings 411 through which signalscan be supplied. The wirings 411 are provided with the terminal 419.Note that the FPC 409(1) through which a signal such as an image signalor a synchronization signal can be supplied is electrically connected tothe terminal 419.

Note that a printed wiring board (PWB) may be attached to the FPC409(1).

The display portion 401 includes wirings such as scan lines, signallines, and power supply lines. Any of various conductive films can beused as the wirings.

Specifically, a metal element selected from aluminum, chromium, copper,tantalum, titanium, molybdenum, tungsten, nickel, yttrium, zirconium,silver, and manganese; an alloy including any of the above-describedmetal elements; an alloy including any of the above-described metalelements in combination; or the like can be used. In particular, one ormore elements selected from aluminum, chromium, copper, tantalum,titanium, molybdenum, and tungsten are preferably included. Inparticular, an alloy of copper and manganese is suitably used inmicrofabrication with the use of a wet etching method.

Specifically, a two-layer structure in which a titanium film is stackedover an aluminum film, a two-layer structure in which a titanium film isstacked over a titanium nitride film, a two-layer structure in which atungsten film is stacked over a titanium nitride film, a two-layerstructure in which a tungsten film is stacked over a tantalum nitridefilm or a tungsten nitride film, a three-layer structure in which atitanium film, an aluminum film, and a titanium film are stacked in thisorder, or the like can be used.

Specifically, a stacked structure in which a film of an element selectedfrom titanium, tantalum, tungsten, molybdenum, chromium, neodymium, andscandium, an alloy film including some of these elements, or a nitridefilm of any of these elements is stacked over an aluminum film can beused.

Alternatively, a light-transmitting conductive material including indiumoxide, tin oxide, or zinc oxide may be used.

<Modification Example 1 of Display Portion>

Any of various kinds of transistors can be used in the display portion401.

A structure in the case of using bottom-gate transistors in the displayportion 401 is illustrated in FIGS. 6A and 6B.

For example, a semiconductor layer containing an oxide semiconductor,amorphous silicon, or the like can be used in the transistor 402 t andthe transistor 403 t illustrated in FIG. 6A.

For example, a film represented by an In-M-Zn oxide that contains atleast indium (In), zinc (Zn), and M (M is a metal such as Al, Ga, Ge, Y,Zr, Sn, La, Ce, or Hf) is preferably included. Moreover, both In and Znare preferably contained.

As a stabilizer, gallium (Ga), tin (Sn), hafnium (Hf), aluminum (Al),zirconium (Zr), or the like can be used. As another stabilizer,lanthanoid such as lanthanum (La), cerium (Ce), praseodymium (Pr),neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium(Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm),ytterbium (Yb), or lutetium (Lu) can be used.

As an oxide semiconductor included in an oxide semiconductor film, anyof the followings can be used, for example: an In—Ga—Zn-based oxide, anIn—Al—Zn-based oxide, an In—Sn—Zn-based oxide, an In—Hf—Zn-based oxide,an In—La—Zn-based oxide, an In—Ce—Zn-based oxide, an In—Pr—Zn-basedoxide, an In—Nd—Zn-based oxide, an In—Sm—Zn-based oxide, anIn—Eu—Zn-based oxide, an In—Gd—Zn-based oxide, an In—Tb—Zn-based oxide,an In—Dy—Zn-based oxide, an In—Ho—Zn-based oxide, an In—Er—Zn-basedoxide, an In—Tm—Zn-based oxide, an In—Yb—Zn-based oxide, anIn—Lu—Zn-based oxide, an In—Sn—Ga—Zn-based oxide, an In—Hf—Ga—Zn-basedoxide, an In—Al—Ga—Zn-based oxide, an In—Sn—Al—Zn-based oxide, anIn—Sn—Hf—Zn-based oxide, an In—Hf—Al—Zn-based oxide, and an In—Ga-basedoxide.

Note that here, for example, an “In—Ga—Zn-based oxide” means an oxidecontaining In, Ga, and Zn as its main components and there is nolimitation on the ratio of In:Ga:Zn. The In—Ga—Z-based oxide may containanother metal element in addition to In, Ga, and Zn.

For example, a semiconductor layer containing polycrystalline siliconthat is obtained by crystallization process such as laser annealing canbe used in the transistor 402 t and the transistor 403 t illustrated inFIG. 6B.

A structure in the case of using top-gate transistors in the displayportion 401 is illustrated in FIG. 6C.

For example, a semiconductor layer including polycrystalline silicon, asingle crystal silicon film that is transferred from a single crystalsilicon substrate, or the like can be used in the transistor 402 t andthe transistor 403 t illustrated in FIG. 6C.

This embodiment can be implemented in appropriate combination with anyof the other embodiments in this specification.

Embodiment 5

In this embodiment, a structure of a foldable touch panel that can beused in the display device of one embodiment of the present inventionwill be described with reference to FIGS. 7A to 7C.

FIGS. 7A to 7C are cross-sectional views illustrating a structure of atouch panel 400B.

The touch panel 400B described in this embodiment is different from thetouch panel 400 described in Embodiment 4 in that the display portion401 displays received image data to the side where the transistors areprovided and that the touch sensor is provided on the substrate 410 sideof the display portion. Different structures will be described in detailbelow, and the above description is referred to for the other similarstructures.

<Display Portion>

The display portion 401 includes a plurality of pixels arranged in amatrix. Each of the pixels includes a display element and a pixelcircuit for driving the display element.

<<Structure of Pixel>>

A pixel includes the sub-pixel 402R, and the sub-pixel 402R includes alight-emitting module 480R.

The sub-pixel 402R includes the first light-emitting element 450R andthe pixel circuit that can supply electric power to the firstlight-emitting element 450R and includes the transistor 402 t.

The light-emitting module 480R includes the first light-emitting element450R and an optical element (e.g., the first coloring layer 467R).

The first light-emitting element 450R includes a lower electrode, anupper electrode, and a layer containing a light-emitting organiccompound between the lower electrode and the upper electrode.

The light-emitting module 480R includes the first coloring layer 467R onthe light extraction side. The coloring layer transmits light of aparticular wavelength and is, for example, a layer that selectivelytransmits light of red, green, or blue color. Note that in anothersub-pixel, a region that transmits light emitted from the light-emittingelement as it is may be provided as well.

The first coloring layer 467R is positioned in a region overlapping withthe first light-emitting element 450R. The first light-emitting element450R illustrated in FIG. 7A emits light to the side where the transistor402 t is provided. Accordingly, part of light emitted from the firstlight-emitting element 450R passes through the first coloring layer 467Rand is emitted to the outside of the light-emitting module 480R asindicated by an arrow in FIG. 7A.

<<Structure of Display Portion>>

The display portion 401 includes a light-blocking layer 467BM on thelight extraction side. The light-blocking layer 467BM is provided so asto surround the coloring layer (e.g., the first coloring layer 467R).

The display portion 401 includes an insulating film 421. The insulatingfilm 421 covers the transistor 402 t. Note that the insulating film 421can be used as a layer for planarizing unevenness caused by the pixelcircuits. A stacked film including a layer that can prevent diffusion ofimpurities can be used as the insulating film 421. This can preventreliability of the transistor 402 t or the like from being lowered bydiffusion of unintentional impurities from the first coloring layer467R.

<Touch Sensor>

The touch sensor 495 is provided on the substrate 410 side of thedisplay portion 401 (see FIG. 7A).

The resin layer 497 is provided between the substrate 410 and thesubstrate 490 and attaches the touch sensor 495 to the display portion401.

<Modification Example 1 of Display Portion>

Any of various kinds of transistors can be used in the display portion401.

A structure in the case of using bottom-gate transistors in the displayportion 401 is illustrated in FIGS. 7A and 7B.

For example, a semiconductor layer containing an oxide semiconductor,amorphous silicon, or the like can be used in the transistor 402 t andthe transistor 403 t illustrated in FIG. 7A. In the transistors, achannel formation region may be sandwiched between upper and lower gateelectrodes, in which case variations in characteristics of thetransistors can be prevented and thus the reliability can be increased.

For example, a semiconductor layer containing polycrystalline silicon orthe like can be used in the transistor 402 t and the transistor 403 tillustrated in FIG. 7B.

A structure in the case of using top-gate transistors in the displayportion 401 is illustrated in FIG. 7C.

For example, a semiconductor layer including polycrystalline silicon, atransferred single crystal silicon film, or the like can be used in thetransistor 402 t and the transistor 403 t illustrated in FIG. 7C.

This embodiment can be implemented in appropriate combination with anyof the other embodiments in this specification.

EXPLANATION OF REFERENCE

200: display panel, 200L: end, 200R: end, 201: display region, 202:pixel, 202B: sub-pixel, 202G: sub-pixel, 202R: sub-pixel, 202 t:transistor, 203 c: capacitor, 203 g: scan line driver circuit, 203 s:data line driver circuit, 203 t: transistor, 210: substrate, 210 a:barrier film, 210 b: substrate, 210 c: adhesive layer, 211: wiring, 219:terminal, 221: insulating film, 228: partition wall, 229: spacer, 250R:light-emitting element, 251R: lower electrode, 252: upper electrode,253: layer, 253 a: light-emitting unit, 253 b: light-emitting unit, 254:intermediate layer, 260: sealant, 267BM: light-blocking layer, 267 p:anti-reflective layer, 267R: coloring layer, 270: counter substrate, 270a: barrier film, 270 b: substrate, 270 c: adhesive layer, 280B:light-emitting module, 280G: light-emitting module, 280R: light-emittingmodule, 300: touch panel, 301: display portion, 302: pixel, 302B:sub-pixel, 302G: sub-pixel, 302R: sub-pixel, 302 t: transistor, 303 c:capacitor, 303 g(1): scan line driver circuit, 303 g(2): imaging pixeldriver circuit, 303 s(1): image signal line driver circuit, 303 s(2):imaging signal line driver circuit, 303 t: transistor, 308: imagingpixel, 308 p: photoelectric conversion element, 308 t: transistor, 309:FPC, 310: substrate, 310 a: barrier film, 310 b: substrate, 310 c: resinlayer, 311: wiring, 319: terminal, 321: insulating film, 328: partitionwall, 329: spacer, 350R: light-emitting element, 351R: lower electrode,352: upper electrode, 353: layer, 353 a: light-emitting unit, 353 b:light-emitting unit, 354: intermediate layer, 360: sealant, 367BM:light-blocking layer, 367 p: anti-reflective layer, 367R: coloringlayer, 370: counter substrate, 370 a: barrier film, 370 b: substrate,370 c: resin layer, 380B: light-emitting module, 380G: light-emittingmodule, 380R: light-emitting module, 400: touch panel, 400B: touchpanel, 401: display portion, 402R: sub-pixel, 402 t: transistor, 403 c:capacitor, 403 g: scan line driver circuit, 403 t: transistor, 409: FPC,410: substrate, 410 a: barrier film, 410 b: substrate, 410 c: resinlayer, 411: wiring, 419: terminal, 421: insulating film, 428: partitionwall, 450R: light-emitting element, 460: sealant, 467BM: light-blockinglayer, 467 p: anti-reflective layer, 467R: coloring layer, 470:substrate, 470 a: barrier film, 470 b: substrate, 470 c: resin layer,480R: light-emitting module, 490: substrate, 491: electrode, 492:electrode, 493: insulating layer, 494: wiring, 495: touch sensor, 497:resin layer, 498: wiring, 499: connection layer, 500: display device,510L: housing, 510L(a): side surface, 510L(b): side surface, 510R:housing, 515L: opening portion, 515R: opening portion, 516L: guide,520L: storage portion, 520R: storage portion, 521L: pulling mechanism,523L: slider, 525L: rail, 550: mechanism.

This application is based on Japanese Patent Application serial no.2013-090859 filed with Japan Patent Office on Apr. 24, 2013, the entirecontents of which are hereby incorporated by reference.

The invention claimed is:
 1. A display device comprising: a hinge; afirst housing connected to the hinge, the first housing including afirst storage portion and a first opening portion; a second housingconnected to the hinge, the second housing including a second storageportion and a second opening portion; and a flexible display panel,wherein the first housing and the second housing are configured to befoldable at the hinge, wherein the flexible display panel is configuredto be stored in the first storage portion through the first openingportion, and to be drawn from the first storage portion through thefirst opening portion, wherein the flexible display panel is configuredto be stored in the second storage portion through the second openingportion and to be drawn from the second storage portion through thesecond opening portion, wherein the flexible display panel extends alonga plane between the first opening portion and the second opening portionwhen the display device is folded halfway, and wherein the flexibledisplay panel is retracted within the first housing and the secondhousing and surrounded by the first housing and the second housing whenthe display device is in a closed position.
 2. The display deviceaccording to claim 1, wherein the first housing further comprises afirst pulling mechanism in the first storage portion, wherein the secondhousing further comprises a second pulling mechanism in the secondstorage portion, wherein the first pulling mechanism is configured topull one end of the flexible display panel, wherein the second pullingmechanism is configured to pull the other end of the flexible displaypanel, wherein the one end of the flexible display panel is configuredto move linearly in a direction.
 3. The display device according toclaim 1, wherein one end of the first housing and one end of the secondhousing are fixed to each other through the hinge.
 4. The display deviceaccording to claim 1, wherein the first opening portion includes a guidehaving a curvature radius of more than or equal to 1 mm and less than orequal to 10 mm on a hinge side.
 5. The display device according to claim1, wherein the first housing comprises a window that enables a displaysurface of the flexible display panel stored in the first storageportion to be observed through the window.
 6. The display deviceaccording to claim 5, wherein the first housing comprises a first outersurface comprising the first opening portion and a second outer surface,wherein the first outer surface and the second outer surface are onopposite sides of the first housing, and wherein the second outersurface includes the window.
 7. The display device according to claim 1,wherein the flexible display panel comprises a transistor including anoxide semiconductor.
 8. The display device according to claim 1, whereinthe flexible display panel further comprises a touch sensor.
 9. Adisplay device comprising: a hinge; a first housing connected to thehinge, the first housing including a first storage portion, a firstpulling mechanism in the first storage portion and a first openingportion, a second housing connected to the hinge; and a flexible displaypanel, one end of the flexible display panel connected to the secondhousing, wherein one end of the first housing and one end of the secondhousing are fixed to each other through the hinge, wherein the firsthousing and the second housing are configured to be foldable at thehinge, wherein the first pulling mechanism is configured to pull theother end of the flexible display panel, wherein the flexible displaypanel is configured to be stored in the first storage portion throughthe first opening portion, and to be drawn from the first storageportion through the first opening portion, wherein the flexible displaypanel extends along a plane between the first opening portion and theother end of the second housing when the display device is foldedhalfway, and wherein the flexible display panel is retracted within thefirst housing and surrounded by the first housing when the displaydevice is in a closed position.
 10. The display device according toclaim 9, wherein the other end of the flexible display panel isconfigured to move linearly in a direction.
 11. The display deviceaccording to claim 9, wherein the first opening portion includes a guidehaving a curvature radius of more than or equal to 1 mm and less than orequal to 10 mm on a hinge side.
 12. The display device according toclaim 9, wherein the first housing comprises a window that enables adisplay surface of the flexible display panel stored in the firststorage portion to be observed through the window.
 13. The displaydevice according to claim 12, wherein the first housing comprises afirst outer surface comprising the first opening portion and a secondouter surface, wherein the first outer surface and the second outersurface are on opposite sides of the first housing, and wherein thesecond outer surface includes the window.
 14. The display deviceaccording to claim 9, wherein the flexible display panel comprises atransistor including an oxide semiconductor.
 15. The display deviceaccording to claim 9, wherein the flexible display panel furthercomprises a touch sensor.